An Exploration of Enzyme Activity Introduction The chemical hydrogen peroxide (H2O2) spontaneously decomposes into water and oxygen gas:
2 H2O2-->2H2O + O2 The reaction happens very slowly, but over a number of years a bottle of peroxide will convert almost entirely into water.
The enzyme CATALASE dramatically speeds the breakdown of hydrogen peroxide. Catalase exists in the cells of many organisms, including humans, to reduce levels of H2O2 that accumulate as a metabolic byproduct. The rate of the catalyzed breakdown of hydrogen peroxide can be measured by the rate of O2 production.
In this investigation, the speed with which O2 bubbles cause a paper disk to rise indicates the relative SPEED of the reaction. Your source of the enzyme will be yeast (Saccharomyces cerevisiae) cells.
I. The tool for Measuring Reaction Rate Before starting, you will learn how to measure the rate of the enzyme-catalyzed reaction. * Obtain a disk of filter paper. * Drop disk into beaker with yeast/enzyme solution and let soak for a few minutes, * Meanwhile, fill a small beaker or plastic cup with 2/3 hydrogen peroxide * Use tweezers to move the paper disk from the yeast and into the hydrogen peroxide. The disk will sink to the bottom- begin timing at the moment the disk touches the bottom! * The disk will float to the surface as it fills with oxygen bubbles produced by the breakdown of H2O2. * Stop timing when disk reaches top. Record in chart below * Perform 2 more trials, and record.
1st Trial
2nd Trial
3rd Trial
Time (in seconds
Hypothesis:
If the paper disk is more soaked with catalase, then it will float to the top of the beaker faster.
Introduction
The chemical hydrogen peroxide (H2O2) spontaneously decomposes into water and oxygen gas:
2 H2O2 --> 2H2O + O2
The reaction happens very slowly, but over a number of years a bottle of peroxide will convert almost entirely into water.
The enzyme CATALASE dramatically speeds the breakdown of hydrogen peroxide. Catalase exists in the cells of many organisms, including humans, to reduce levels of H2O2 that accumulate as a metabolic byproduct. The rate of the catalyzed breakdown of hydrogen peroxide can be measured by the rate of O2 production.
In this investigation, the speed with which O2 bubbles cause a paper disk to rise indicates the relative SPEED of the reaction. Your source of the enzyme will be yeast (Saccharomyces cerevisiae) cells.
I. The tool for Measuring Reaction Rate
Before starting, you will learn how to measure the rate of the enzyme-catalyzed reaction.
* Obtain a disk of filter paper.
* Drop disk into beaker with yeast/enzyme solution and let soak for a few minutes,
* Meanwhile, fill a small beaker or plastic cup with 2/3 hydrogen peroxide
* Use tweezers to move the paper disk from the yeast and into the hydrogen peroxide. The disk will sink to the bottom- begin timing at the moment the disk touches the bottom!
* The disk will float to the surface as it fills with oxygen bubbles produced by the breakdown of H2O2.
* Stop timing when disk reaches top. Record in chart below
* Perform 2 more trials, and record.
Hypothesis:
If the paper disk is more soaked with catalase, then it will float to the top of the beaker faster.